Capacitive touch sensors are known and ubiquitous. Their basic operation is relatively simple. A capacitive touch sensor typically is a small capacitor enclosed in an electrical insulator. The capacitor is a device that has an ability to store an electrical charge, referred to as capacitance. When a power source applies an increased voltage across the capacitor, electrical charges flow into the capacitor until the capacitor is charged to the increased voltage. Similarly, when the power source applies a decreased voltage the capacitor, electrical charges flow out of the capacitor until the capacitor is discharged to the decreased voltage. The amount of time it takes for the capacitor to charge or discharge is dependent on the change in voltage applied and the capacitance of the capacitor. Thus if the capacitance is unknown, it can calculated from the charge or discharge time and the change in voltage applied. A person touching or coming close to a capacitive touch sensor can change the sensor's effective capacitance by combining the person's capacitance with the capacitance of the capacitive touch sensor. This change in effective capacitance can be detected by a change in the charge or discharge times.
Most common capacitive touch sensors, such as those used in cell phones and ATMs are made on inflexible substrates several millimeters thick and protected by glass. Thin film capacitive touch sensors are known, such as those taught in U.S. Pat. No. 6,819,316 “Flexible capacitive touch sensor.” However, thin film capacitive touch sensors not used as much due to several technical challenges, including a “two-sided” effect that makes thin film capacitive touch sensors sensitive to touch on both sides of the sensor.
A recent proliferation of inexpensive computer processors and logic devices has influenced games, toys, books, and the like. For example, some kinds of games, toys, and books use embedded sensors in conjunction with control logic coupled to audio and/or visual input/output logic to enrich the interactive experience provided by the game, toy, book, or the like. An example is a book or card (e.g., greeting card) that can sense the identity of an open page or card and provide auditory feedback to the reader relevant to the content of the open page or card.
Many conventional stand-alone computer games provide a visual display of game activity through an electronic display system such as a pixilated flat panel display. Such displays lack the three-dimensional character and physical interaction inherent in typical board-based games. For example, a conventional board game may use of one or more movable playing pieces integral to the action of the game. Conversely, conventional board games often lack the audio and/or visual interaction and computerized game play offered by computer games.
A number of prior art patents have described games (e.g., board games), toys, books, and cards that utilize computers and sensors to detect human interaction with elements of the board games, toys, books, and cards. The following represents a list of known related art:
Date ofReference:Issued to:Issue/Publication:U.S. Pat. No. 5,645,432JessopJul. 8, 1997U.S. Pat. No. 5,538,430Smith et al.Jul. 23, 1996U.S. Pat. No. 4,299,041WilsonNov. 10, 1981U.S. Pat. No. 6,955,603Jeffway, Jr. et alOct. 18, 2005U.S. Pat. No. 6,168,158BulsinkJan. 2, 2001U.S. Pat. No. 5,853,327GilboaDec. 29, 1998U.S. Pat. No. 5,413,518LinMay 9, 1995U.S. Pat. No. 5,188,368RyanFeb. 23, 1993U.S. Pat. No. 5,129,654BognerJul. 14, 1992
The teachings of each of the above-listed citations (which does not itself incorporate essential material by reference) are herein incorporated by reference. None of the above inventions and patents, taken either singularly or in combination, is seen to describe an embodiment or embodiments of the instant invention described below and claimed herein.
For example, U.S. Pat. No. 5,853,327 “Computerized Game Board” describes a system that automatically senses the position of toy figures relative to a game board and thereby supplies input to a computerized game system. The system requires that each game piece to be sensed incorporate a transponder, which receives an excitatory electromagnetic signal from a signal generator and produces a response signal that is detected by one or more sensors embedded in the game board. The complexity and cost of such a system make it impractical for low-cost games and toys.
U.S. Pat. No. 5,129,654 “Electronic Game Apparatus,” U.S. Pat. No. 5,188,368 “Electronic Game Apparatus,” and U.S. Pat. No. 6,168,158 “Device for Detecting Playing Pieces on a Board” all describe systems using resonance frequency sensing to determine the position and/or identity of a game piece. Each system requires a resonator circuit coupled with some particular feature of each unique game piece, which increases the complexity and cost of the system while reducing the flexibility of use.
U.S. Pat. No. 5,413,518 “Proximity Responsive Toy” describes another example of a toy incorporating automatic sensing that utilizes a capacitive sensor coupled to a high frequency oscillator, whereby the frequency of the oscillator is determined in part by the proximity of any conductive object (such as a human hand) to the capacitive sensor. This system has the disadvantages of requiring specialized electronic circuitry that may limit the number of sensors that can be simultaneously deployed.
U.S. Pat. No. 6,955,603 “Interactive Gaming Device Capable of Perceiving User Movement” describes another approach to sensing player interaction by using a series of light emitters and light detectors to measure the intensity of light reflected from a player's hand or other body part. Such a system requires numerous expensive light emitters and light detectors, in particular for increasing the spatial sensitivity for detection.
U.S. Pat. No. 5,645,432 “Toy or Educational Device” describes a toy or educational device that includes front and back covers, a spine, a plurality of pages, a plurality of pressure sensors mounted in the front and back covers and a sound generator connected to the pressure sensors. The pressure sensors are responsive to the application of pressure to an aligned location of a page overlying the corresponding cover for actuating the sound generator to generate sounds associated with both the location of the sensor which is depressed and the page to which pressure is applied.
U.S. Pat. No. 5,538,430 “Self-reading Child's Book” describes a self-reading electronic child's book that displays a sequence of indicia, such as words, and has under each indicia a visual indicator such as a light-emitting diode with the visual indicators being automatically illuminated in sequence as the child touches a switch associated with each light-emitting diode to sequentially drive a voice synthesizer that audibilizes the indicia or word associated with the light and switch that was activated.
U.S. Pat. No. 4,299,041 “Animated Device” describes a device in the form of a greeting card, display card, or the like, for producing a visual and/or a sound effect that includes a panel member or the like onto which is applied pictorial and/or printed matter in association with an effects generator, an electronic circuit mounted on the panel member but not visible to the reader of the matter but to which the effects generator is connected, and an activator on the panel member, which, when actuated, causes triggering of the electronic circuit to energize the effects generator.
Each of the prior art patents included above describes a game, toy, book, and/or card that requires expensive components or manufacturing techniques and/or exhibits limited functionality. As will be described below, embodiments of the present invention overcome these limitations